title: The Drosophila nuclear lamina protein otefin is required for germline stem cell survival.
abstract: LEM domain (LEM-D) proteins are components of an extensive protein network that assembles beneath the inner nuclear envelope. Defects in LEM-D proteins cause tissue-restricted human diseases associated with altered stem cell homeostasis. Otefin (Ote) is a Drosophila LEM-D protein that is intrinsically required for female germline stem cell (GSC) maintenance. Previous studies linked Ote loss with transcriptional activation of the key differentiation gene bag-of-marbles (bam), leading to the model in which Ote tethers the bam gene to the nuclear periphery for gene silencing. Using genetic and phenotypic analyses of multiple ote(-/-) backgrounds, we obtained evidence that is inconsistent with this model. We show that bam repression is maintained in ote(-/-) GSCs and that germ cell loss persists in ote(-/-), bam(-/-) mutants, together demonstrating that GSC loss is independent of bam transcription. We show that the primary defect in ote(-/-) GSCs is a block of differentiation, which ultimately leads to germ cell death.
authors.affiliation: Department of Biochemistry, University of Iowa, College of Medicine, Iowa City, IA 52242, USA.
authors.forename: Lacy J
authors.initials: LJ
authors.lastname: Barton
authors.forename: Belinda S
authors.initials: BS
authors.lastname: Pinto
authors.forename: Lori L
authors.initials: LL
authors.lastname: Wallrath
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Geyer
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005854:Germ Cells / Q000166:cytology / Q000502:physiology*; D018095:Germ-Line Mutation / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D034881:Nuclear Lamina / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C063595:Ote protein, Drosophila; C091674:bam protein, Drosophila